The present invention is particularly related to puffer-type compressed-gas circuit-interrupters of the type in which only a single gas pressure is utilized within the interrupting container structure, and a difference of pressure for arc interruption is achieved by relative piston action, that is, relative movement of an operating cylinder to a cooperable piston structure.
As is well known by those skilled in the art, the relative motion between a movable operating cylinder assembly and a cooperable fixed piston achieves a desirable compression of gas therebetween within the intervening compression chamber, which compressed gas is utilized during arc interruption by generally forcing the compressed high-pressure gas through a movable nozzle structure to direct the high-pressure gas flow intimately into engagement with the established arc located within the movable nozzle structure to effect the arc's extinction.
The present invention relates to puffer-type circuit-interrupters of the type set forth in U.S. Pat. No. 3,551,623, issued Dec. 29, 1970 to Colcaser et al. This patent shows the relative motion of a movable piston within a relatively stationary operating cylinder, with electromagnetic field coils energizing a companion movable piston, which is electrically repelled toward the first-mentioned movable piston, the latter being attached to, and movable with, a contact-operating rod.
As is well known by those skilled in the art, there are many patents treating different piston structures, for example, U.S. Pat. No. 2,429,311, issued Oct. 21, 1947 to Gay; U.S. Pat. No. 3,786,215, issued Jan. 15, 1974 to Mauphe; and U.S. Pat. No. 3,987,262 issued Oct. 19, 1976 to Rostron.
An additional patent of interest in connection with piston structures is U.S. Pat. No. 3,331,935, issued July 18, 1967 to Milianowicz. Another piston patent, utilizing hydraulic action for effecting piston action, is U.S. Pat. No. 2,913,559, issued Nov. 17, 1959 to Cromer. An additional patent of interest is German Pat. No. 671,326 patented in Germany October, 1937.
All of the aforesaid patents indicate that piston structures of the prior art are well known, but many have deficiencies of complexity and of being rather slow in operation. In addition, back-pressure gas conditions may easily arise, which renders the interrupter, as a whole, relatively slow-acting in operation.